For the 2nd week of BFA, M+, Raids, and Rated PvP are still not open so there isn’t that much that you have to do. Do your Island Expos to level up your Heart of Azeroth, do WQs for rewards, do Warfronts and the 11 weekly quest turn ins, and run your Mythic Dungeons again to try to get the most gear before reset. I personally will be spending a lot of Week 2 farming mats for consumables for M+ and Raids but whatever you choose to do is up to you.
If you bought Legion and have no desire to go through old content, good news! The new expansion comes with a free boost to level 100 for one character. You can buy these boosts from the in-game store whenever you want, but they normally cost $60, so savor this free one. Use it for a class that you are confident you will enjoy. As a fresh level 100 character, you will be able to immediately begin the quest that takes you the Broken Isles, the new region where Legion takes place.
Professions: This may seem strange for a leveling guide, but the first opportunity you get, pick up both the Mining and Herbalism gathering professions. Not only will this allow you to track many various quest objectives on your map, but you also get a fair amount of experience whenever you gather. I'd put it at around 10% of a quest turn-in per gather. Since most of your wasted time in WoW is travel time, stopping to gather ore or herbs can keep your exp/h rolling as long as you don't go too far out of your way. You should only gather if it's convenient, and on the way to an actual quest objective. Don't make gathering your priority.
It's not an enchantment, but you should buy or craft an iLVL 100+ belt, gloves, or boots with a gem socket for use with the new 5% bonus experience gem: Insightful Rubellite. I used a vendor-bought belt from the legacy valor vendor in Orgrimmar, since it was convenient and met the minimum ilvl bonus. Keep these in your bags until you can equip them, which should be just in time for treasure collections in WoD content. I didn't ever replace the belt until I dinged 110, since I didn't feel the stats from later upgraded belt drops made enough of a difference to outweigh the 5% bonus. This is explained below, in the WoD treasure section.
Even though the guide was developed with a hunter, the guide can be followed by any class. Except you have to do your class's quests which aren't a whole lot. I do have full intention to make my guide friendly with all classes in the future by listing all of their steps as well. There will be a toggle that allows you to show which class's steps you want to see in the guide. But this is coming later.
The community was apparently frustrated with Blizzard for a lack of communication concerning the issue, but it looks like that was due to the fact that their heads were down as they worked to understand the problem. It was explained that they didn't want to just roll out a quick bandage, as that would likely cause unforeseen issues down the road. Instead, they're crunching the numbers and digging into the code in the hopes of discovering a legitimate source of the problem.
I made one for my guildies but its for the Horde leveling process. One tip that goes for both factions is that you dont need to do all 3 zones to hit 120. I did like 1 and than three quarters of another. But once your 120 you need friendly with all 3 of your factions new reps to unlock world quests so make sure you hit at least friendly with all 3 while your leveling.